(USATODAY.com) - Major League Baseball Commissioner Bud Selig is fond of saying, "Baseball is a social institution." With the U.S. Supreme Court debating the constitutionality of same-sex marriage today, the game's societal role might be a step closer to facing a test and an opportunity.
A verdict in favor of gay marriage would represent another major breakthrough toward acceptance for a movement that continues to gather momentum - except in pro team sports.
Baseball blazed the trail toward racial equality when Jackie Robinson broke the color barrier in 1947, a historic achievement chronicled in the film 42, due out April 12, three days before the 66th anniversary of Robinson's debut.
Is the sport ready to take on a pioneering role when it comes to homosexual players and perhaps have the first openly gay active athlete in North America's four major sports? The signs have been mixed.
"I have great faith in the players, and I think baseball will be a leader on this issue; I really do," says Rob Manfred, MLB's executive vice president of labor relations.
One could argue baseball has fallen behind. Last week, an alliance of athletes joined NFL players Brendon Ayanbadejo, Scott Fujita and Chris Kluwe in supporting their brief filed to the Supreme Court challenging California's ban on same-sex marriage. The names of 10 current NFL players and representatives from North America's other major sports leagues are on the brief, but none is from baseball.
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But Ayanbadejo, the Baltimore Ravens linebacker who used the Super Bowl as a platform to advocate for marriage equality, says he believes baseball's environment might be most conducive for a player to come out. He played the sport for 12 years as a youth and has interacted with many major league players.
"Honestly, I think it will happen in baseball sooner than in football or basketball," Ayanbadejo told USA TODAY Sports. "The reason I say that is because I think there is less of a connection to religion in baseball. The religious roots are a lot deeper in basketball and football. I could be wrong. But I just felt that they were a bit more open-minded."
Still, the reality of a major league clubhouse might suggest otherwise.
MLB made strides by adding language barring discrimination based on sexual orientation to its latest collective bargaining agreement, signed in November 2011. But the measure, suggested by the players association, was taken for legal reasons and not because of a desire to make a social statement, union chief Michael Weiner acknowledges.
"I think (being an openly gay player) would be extremely difficult because of the culture," says Toronto Blue Jays pitcher Brandon Morrow, adding he would be fine with it. "Not that I think there's a lot of anti-gay sentiment around, it's just that masculine feel in the clubhouse."
'It's going to keep evolving'
Teammate reaction stands as one of the biggest unsolved questions - and likely most imposing obstacle - regarding a player coming out. The issue is particularly relevant in baseball because teammates are together for the better part of eight months, including spring training.
During a news media session last month in Phoenix, three current managers who were asked about the game's readiness for an openly gay player declined to address the subject. The general manager of an American League team, speaking on condition of anonymity because of the sensitive nature of the topic, said he would welcome an openly gay player on his roster but doesn't think the game is ready for that step.
"Like in Jackie Robinson's case, if you're good enough, you're going to get accepted," Los Angeles Dodgers manager Don Mattingly says. "How ready is the game? I don't know. ... But (the Dodgers) have a female trainer. I just think we're probably more ready than 10 years ago. And 10 years from now, we would probably be more ready then. It's going to keep evolving."
When he joined the Dodgers in 1976, Cincinnati Reds manager Dusty Baker played with Glenn Burke, who along with ex-outfielder Billy Bean are the two former major leaguers known to have publicly come out after their playing days.
Baker says Burke, who died of AIDS in 1995, was "like my little brother," yet he didn't know Burke was gay until a mutual friend who is a lesbian pointed it out.
Much like Burke kept his sexuality a secret, Baker figures gay players are doing the same now.
"I don't think the world is at that stage (of accepting them)," Baker said. "It's not baseball. It's the world."
An increasing number of high-profile players are publicly expressing their willingness to accept a gay teammate. They include Detroit Tigers ace Justin Verlander and, among those interviewed for this story, All-Stars such as David Ortiz, Jose Bautista, Kevin Youkilis, Prince Fielder, C.J. Wilson and Carlos Gonzalez.
That might simply reflect a keen media awareness. After all, it was hard to miss how San Francisco 49ers cornerback Chris Culliver was pilloried after saying during Super Bowl week that he couldn't play with a gay teammate.
And last season, Toronto Blue Jays shortstop Yunel Escobar was suspended for three games when he took the field with a homophobic slur written in Spanish on his eye black.
But there are also signs of growing openness among players. Youkilis, for example, offered his support two years ago when Boston Herald columnist Steve Buckley came out.
If a teammate took a similar step, "I'd applaud the guy, because it's not an easy task," says Youkilis, now with the New York Yankees. "I'd accept him on my team."
Last season while with the Oakland Athletics, pitcher Brandon McCarthy sent out a tweet denouncing as homophobic the practice in some stadiums of focusing the camera on two men as a joke during the Kiss Cam bit that runs on the scoreboard.
He and teammates Dallas Braden and Jemile Weeks filmed a spot for the It Gets Better campaign, which seeks to support gay, lesbian, bisexual and transgender teens who have felt bullied or harassed.
McCarthy says the argument that an openly gay player could make teammates uncomfortable in the clubhouse environment is silly.
"If you've played this game for a number of years, you've probably had a few gay teammates, and have you been accosted in the shower yet?" McCarthy says. "It's probably not going to happen if someone comes out."
Watch for 'hateful' words
The ones who most frequently feel uncomfortable are the closeted gay athletes, says Patrick Burke, co-founder of the You Can Play Project, which seeks to foster an atmosphere of inclusion for LGBT athletes.
Burke provided guidance to the Blue Jays and Escobar after his incident, and he addressed the team's players this month.
Burke emphasizes the impact homophobic terms can have, even when used in a joking manner not intended as an insult, as Escobar said was the case with his eye-black message.
"What we educate them on is that it's not just a word," Burke says. "If you have a closeted gay player in your locker room, what they're listening to is, 'That guy won't support me. I can't be myself around him.'"
To make sure that message reached the Blue Jays' Latino players, Burke brought along Jose Estevez, a gay cross-country runner from Boston College who is of Cuban descent.
About 25% of players in the majors and close to 40% of minor leaguers are from Latin American countries, where views on homosexuality tend to be more conservative.
Latino players often use homophobic terms as part of their clubhouse banter, which in a sense is what got Escobar in trouble.
"We call each other that every two minutes and don't take it so seriously," Escobar says. "But I learned that for the person who's in the closet, hearing that word makes them retreat even further. It's a hateful word for them."
Ortiz and Bautista, Dominican-born veterans known as leaders on their teams, agree that there's less tolerance back home, with Bautista saying homosexuality is "still taboo" but nonetheless believing most fellow Latino players wouldn't have an issue with a gay teammate.
Gonzalez, the Colorado Rockies' multitalented outfielder, offers a perspective rooted in the U.S. credo as a land of diversity.
"The way I see it is I'm a Latin guy who is playing in a country that is giving me the opportunity to play in the best baseball in the world even though I come from a different culture,'' says Gonzalez, who's Venezuelan. "You become part of that system and there's no difference between somebody who's American or Latin. The skin color and the race don't matter. So if that happened (a player coming out), I would have no problem with it.''
Some players believe the biggest deterrent to a gay player making his sexuality public is less the potential clubhouse reception and more the inevitable media attention.
There's little question such a development would create a huge stir extending well beyond the sports realm, and the constant attention may detract from the player's on-field performance.
This spring, Verlander was besieged with media requests after he told CNN he "absolutely'' would be OK with a gay teammate.
"Putting all the microphones in his face or the cameras in his face lends another layer of scrutiny, or just the stress and hassle of answering all those questions,'' McCarthy says. "I think he'd be accepted fine in the clubhouse for the most part.''
"If the guy's good, he's good," says Wilson, a Los Angeles Angels pitcher. "If there's a girl who could throw 100 (mph) and punch everybody out, she would get to play, too. We don't care. Outside, as soon as you leave the locker room, what are you subject to? The fans, the media. They're always going to want to ask questions."
Withstanding a backlash
That's why there's a general belief that the first player to come out would ideally have special character traits, and preferably star-level skills, to withstand any backlash.
Many compare it to Brooklyn Dodgers executive Branch Rickey choosing Robinson as the player to break the color barrier because he combined intestinal fortitude with Hall of Fame playing ability.
"It's good to get on the right side of history," McCarthy says. "You don't want to be the league that's looked on in 10 years where you were behind the times. Unfortunately, we're already a sport that has a checkered past with race. I don't think you want to be behind again now."
Baltimore Orioles outfielder Chris Dickerson, who is African American, sees a correlation between prevailing attitudes toward blacks when Robinson arrived on the scene and the views on homosexuals in sports now.
Gay figures in politics, TV shows and other walks of life are proof of their acceptance, Dickerson says.
"However," he added, "sports is a completely different aspect with the machismo. You'd have to be incredibly brave to come out and to deal with it."
Contributing: Erik Brady, Gabe Lacques, Paul White